16 replies to this topic

[will_nic]

Hi all,

 

I have a 95 SPi Mini which appears to have an aftermarket air con unit fitted. The car was UK built and then spent sometime in Japan (where I believe the AC unit was fitted - however I am just guessing).

 

Since I have owned the car the AC has never blown cold air, but I'd like to get it working. I have no experience with AC, but I'm hoping for a few tips to help try diagnose the issue.

 

I have attached some photos of the unit.

 

What I know:

• The fan speed dial works and does control the speed of the blower - pushes out ambient temp.
• Temp dial does not change temperature
• By memory the AC compressor clutch does engage when the unit is turned on
• I dont know if it has enough or any refrigerant in the system
• Sticker on compressor states refrigerant 'R12', which I believe is now illegal?

 

From doing a bit of reading the thermostat sounds like a common issue... could this be the problem in my car? Where would I find it and test it?

 

Thanks so much in advance,

Will

Attached Files

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•  IMG_2766.jpg   67.89K   3 downloads
•  Interior.jpg   182.08K   2 downloads
•  IMG_9028.JPG   70.74K   1 downloads

[Cooper Mac]

I'm going through a similar project with my 205 GTi's A/C!

 

You are correct, R12 cannot be used anymore, so you will only be able to use R134a, BUT to use this gas, you will need to change all of the  o ring seals in your current system as these are not compatible with the original O rings. If you don't change them, the gas will just leak out!

 

Usually there is a pressure sensor in the system, which prevents the Clutch from engaging if there isn't enough gas in the system. If your clutch does engauge it is either because there is enough gas in the system, or the pressure sensor is faulty.....

 

The fan speed should work independently of the A/C electrical circuits, so what you have seen if OK.

 

I would check that the clutch is engaging, if it isn't that that will be why you don't have and cold air! If the couch is engaging, but you are not getting any cold air, then I would assume that it is the Pump, which isn't pumping...... 

[will_nic]

I'm going through a similar project with my 205 GTi's A/C!

 

You are correct, R12 cannot be used anymore, so you will only be able to use R134a, BUT to use this gas, you will need to change all of the  o ring seals in your current system as these are not compatible with the original O rings. If you don't change them, the gas will just leak out!

 

Usually there is a pressure sensor in the system, which prevents the Clutch from engaging if there isn't enough gas in the system. If your clutch does engauge it is either because there is enough gas in the system, or the pressure sensor is faulty.....

 

The fan speed should work independently of the A/C electrical circuits, so what you have seen if OK.

 

I would check that the clutch is engaging, if it isn't that that will be why you don't have and cold air! If the couch is engaging, but you are not getting any cold air, then I would assume that it is the Pump, which isn't pumping...... 

 

Thanks!

 

Replacing all the o-rings sounds like a big job right? Sounds like something which would be best suited to a AC pro... any suggestions for someone in the midlands?

 

I did wonder if the AC system was drained of gas before it was re-imported into the UK?

 

I will check the compressor clutch this week and report back.

 

Cheers,

Will.

 

Also, good luck with the 205 project!

[Cooper Mac]

The O rings are not too much of a problem (famous last words!) as they will just be on each pipe connection. It's easy for you to do yourself, fortunately the gas had been long gone from my 205, so there was no problem opening the pipe connections and changing the O rings. I got an A/C O ring selection pack off eBay, they are green in colour if that helps?

 

I managed to finish my A/c off and take it to get recharged and tested, but sadly during the pressure test one of the original pipes burst, not a problem other than it is the only one I can't easily get to! I did manage to get an original pipe (a challenge when there were only a handfull of UK 205s that came with A/C!), but fitting it requires removing the front end of the car......

[will_nic]

The O rings are not too much of a problem (famous last words!) as they will just be on each pipe connection. It's easy for you to do yourself, fortunately the gas had been long gone from my 205, so there was no problem opening the pipe connections and changing the O rings. I got an A/C O ring selection pack off eBay, they are green in colour if that helps?

 

I managed to finish my A/c off and take it to get recharged and tested, but sadly during the pressure test one of the original pipes burst, not a problem other than it is the only one I can't easily get to! I did manage to get an original pipe (a challenge when there were only a handfull of UK 205s that came with A/C!), but fitting it requires removing the front end of the car......

 

Hmm, yeah that's my concern. As you can see from the pic's there isnt much space in the engine bay with the A/C haha! I'll have a better look this week.

 

Bummer about the burst pipe on the 205!

[will_nic]

 

 

Alright, so I have tried to see if the AC compressor clutch engages. As far as I can tell it does not. I didn't hear a click or anything when I turned the blower on inside the car, also no change in engine idle. Here is a video as I turn the blower unit on. Listening to the video I can't hear anything either. 

 

I guess my next best bet is to take it to someone to see if there is pressure/refrigerant in the system? 

Is there anyway to test the pressure switch and rule that out first? And where would I find this?

 

It was blowing cold air today, but that was only because it was freezing in the garage haha!

 

Cheers,

Will.

Edited by will_nic, 23 November 2020 - 03:13 PM.

[Cooper Mac]

The Clutch isn't engaging, so it is possible that the system isn't seeing any pressure, or the clutch is NFG! 

 

I don't know anything about the A/C setup on Minis, but if there is a plug on the Compressor pump (there must be so you can remove / swap the pump), then you can remove this and but 12 volts across it to check that the electro magnetic clutch is working. You will need to do this with the engine switched off. If it is working, you will hear and see it move within the pully. It is possible that is it hasn't been used for a while that it might need freeing off with some small taps to the pulley. If the clutch works then it either isn't getting the signal from the A/C control, or the gas is low / gone.

 

The only way to safely check the gas situation is to take it to an A/C specialist so they can check it for you. If there is gas in there, but not enough it would also be safer for them to remove this for you, then you can change the seals and check the system ready for re-gassing!

[will_nic]

The Clutch isn't engaging, so it is possible that the system isn't seeing any pressure, or the clutch is NFG! 

 

I don't know anything about the A/C setup on Minis, but if there is a plug on the Compressor pump (there must be so you can remove / swap the pump), then you can remove this and but 12 volts across it to check that the electro magnetic clutch is working. You will need to do this with the engine switched off. If it is working, you will hear and see it move within the pully. It is possible that is it hasn't been used for a while that it might need freeing off with some small taps to the pulley. If the clutch works then it either isn't getting the signal from the A/C control, or the gas is low / gone.

 

The only way to safely check the gas situation is to take it to an A/C specialist so they can check it for you. If there is gas in there, but not enough it would also be safer for them to remove this for you, then you can change the seals and check the system ready for re-gassing!

 

Cool, thanks man. I'll give it a shot.

 

Cheers,
Will.

[xrocketengineer]

It is probably better to take it to a professional. The O rings themselves might survive the changeover if they are in good shape however, the issue is that R12 uses petroleum based oil and R134a uses synthetic oil. The R12 oil residue can react with the 134a refrigerant and become corrosive. So, the compressor and accumulator have to be removed and drained then flushed like the rest of the system. At this point most of the components have been removed and there is no point on reusing old incompatible O rings. In most cases the accumulator is replaced too.

[will_nic]

It is probably better to take it to a professional. The O rings themselves might survive the changeover if they are in good shape however, the issue is that R12 uses petroleum based oil and R134a uses synthetic oil. The R12 oil residue can react with the 134a refrigerant and become corrosive. So, the compressor and accumulator have to be removed and drained then flushed like the rest of the system. At this point most of the components have been removed and there is no point on reusing old incompatible O rings. In most cases the accumulator is replaced too.

I agree. Not something I particulary want to go wrong. When I get the chance I'll take it to a pro.

 

Cheers for the help all.

[Aria Aradhea]

Yes, the clutch is not engaging. Check if you have enough gas in the system and that it is not leaking somewhere.

 

The thermostat is a common problem because of the position of its location (above the ac fan blower) that tends to kink the cable, but usually will work if it set on the maximum cool position although will cut off often. 

[Bobbins]

It's hard to tell from the first photo, but on my '98 Mini the air-con accumulator is fitted directly over the o/s subframe tower bolt therefore needs to be removed to access the bolt and change the tower rubbers. If the air-con is degassed and having the seals renewed it's wise to take the opportunity to replace the subframe rubber mounts at the same time.

[will_nic]

Thanks guys. I ran 12v to the AC clutch and it did engage (with engine off), so I suspect the system has been degassed, or doesn't have enough.

 

I need to take it to an AC specialist for them to check if there is any refrigerant in the system. I'll hopefully do that once we are out of lockdown.

 

As for the accumulator, I believe my is mounted under the condesor. I recently had to unbolt the subframe and there were no obstructions thankfully.

 

Cheers,
Will.

[Bruiser]

Hi Will, 

I just came across your post from November - regarding the diagnosis, the clutch is just a 12v solenoid effectively, so rig up a positive wire with something like a 15A fuse in it and connect that to the single wire (from memory it earthed via the block) going into the compressor. That will tell you if it is activating - a healthy click. If it does, try then loosening the belt and turning the compressor by hand.

 

I had an old Cadillac that the compressor had seized on, so the previous owner had just cut the wire and pulled the fuse. If it is seized and you get the clutch to pull in you are at risk of trashing your drive belt.

 

Anyway, interesting that you say your car is 95, as the A/C you have fitted is the aftermarket unit from Pre 1990 ish. From 94 onwards all Japan car had factory fitted A/C with 134A done at Longbridge.

 

The 1st car I saw like yours was the kit made by Unicla of Nagoya, Japan. Later, the front mounted condenser that you have was moved to the RH inner wing but was still a Japan fit modification. Then we had the fan cowl welded in during production. I suppose there is a chance a 95 car was shipped out and retro fitted, but it would be a strange thing to do.

 

As for the R12 and the seals, I also have a recollection that both the seals and the Oil in the compressor were unique to R12 and not compatible with 134a, 

 

Hope some of that helps

Chris

[Tornado99]

When I researched retrofitting AC to an '84 VW GTi back in the mid 90's, I recall finding a type of refridgerant that was compatible with mineral oil and seals on R12 systems but permitted under new rules as ozone safe, yet not r134.

Do a google for ac refrigerant types, backward compatible to R12. That would save you changing out seals and components.

Is there a sight glass on the mini system to let you see the fluid moving within? The VW had that on the dryer/accumulator unit.